SceneGraph.hh

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//=============================================================================
//
//  CLASS SceneGraph
//
//=============================================================================

#ifndef ACG_SCENEGRAPH_HH
#define ACG_SCENEGRAPH_HH


//== INCLUDES =================================================================

#include "BaseNode.hh"
#include "DrawModes.hh"
#include "../Math/VectorT.hh"
#include <cfloat>

#include <QMouseEvent>

//== NAMESPACES ===============================================================

namespace ACG {
namespace SceneGraph {


//== CLASS DEFINITION =========================================================

template<bool C, typename T = void>
struct enable_if {
  typedef T type;
};

template<typename T>
struct enable_if<false, T> { };

#define HAS_MEM_FUNC(func) \
    template<typename T, typename Sign>                                               \
    struct has_##func {                                                               \
        template <typename U, U> struct type_check;                                   \
        template <typename _1> static char (& chk(type_check<Sign, &_1::func> *))[1]; \
        template <typename   > static char (& chk(...))[2];                           \
        static bool const value = sizeof(chk<T>(0)) == 1;                             \
    };

HAS_MEM_FUNC(enter)

// if the enter function is implemented
template<typename Action>
typename enable_if<has_enter <Action, void (Action::*) (BaseNode *) >::value, void>::type
if_has_enter(Action &_action, BaseNode *_node) {
  _action.enter (_node);
}

// if the enter function isn't implemented
template<typename Action>
typename enable_if<!has_enter <Action, void (Action::*) (BaseNode *) >::value, void>::type
if_has_enter(Action &, BaseNode *) {
}

HAS_MEM_FUNC(leave)

// if the enter function is implemented
template<typename Action>
typename enable_if<has_leave <Action, void (Action::*) (BaseNode *) >::value, void>::type
if_has_leave(Action &_action, BaseNode *_node) {
  _action.leave (_node);
}

// if the enter function isn't implemented
template<typename Action>
typename enable_if<!has_enter <Action, void (Action::*) (BaseNode *) >::value, void>::type
if_has_leave(Action &, BaseNode *) {
}

//----------------------------------------------------------------------------


template <class Action>
void
traverse( BaseNode* _node, Action& _action )
{
  if (_node)
  {
    BaseNode::StatusMode status(_node->status());


    // If the subtree is hidden, ignore this node and its children while rendering
    if (status != BaseNode::HideSubtree)
    {

      bool process_children(status != BaseNode::HideChildren);

      // If the node itself is hidden, ignore it but continue with its children
      if (_node->status() != BaseNode::HideNode)
      {
        // Executes this nodes enter function (if available)
        if_has_enter (_action, _node);

        // Test rendering order. If NodeFirst, execute this node and the children later.
        if (_node->traverseMode() & BaseNode::NodeFirst)
          process_children &= _action(_node);
      }

      if (process_children)
      {

        BaseNode::ChildIter cIt, cEnd(_node->childrenEnd());

        // Process all children which are not second pass
        for (cIt = _node->childrenBegin(); cIt != cEnd; ++cIt)
          if (~(*cIt)->traverseMode() & BaseNode::SecondPass)
            traverse(*cIt, _action);

        // Process all children which are second pass
        for (cIt = _node->childrenBegin(); cIt != cEnd; ++cIt)
          if ((*cIt)->traverseMode() & BaseNode::SecondPass)
            traverse(*cIt, _action);

      }

      // If the node is not hidden
      if (_node->status() != BaseNode::HideNode)
      {

        // If the children had to be rendered first, we now render the node afterwards
        if (_node->traverseMode() & BaseNode::ChildrenFirst)
          _action(_node);

        // Call the leave function of the node.
        if_has_leave (_action, _node);
      }

    }
  }
}

//---------------------------------------------------------------------------------

template <class Action>
void
traverse_all( BaseNode* _node, Action & _action)
{
    if(_node)
    {
        bool process_children(true);

        // Executes this nodes enter function (if available)
        if_has_enter(_action, _node);

        // Test rendering order. If NodeFirst, execute this node and the children later.
        if(_node->traverseMode() & BaseNode::NodeFirst)
            process_children &= _action(_node);

        if(process_children)
        {
            BaseNode::ChildIter cIt, cEnd(_node->childrenEnd());

            // Process all children which are not second pass
            for (cIt = _node->childrenBegin(); cIt != cEnd; ++cIt)
              if (~(*cIt)->traverseMode() & BaseNode::SecondPass)
                traverse_all(*cIt, _action);

            // Process all children which are second pass
            for (cIt = _node->childrenBegin(); cIt != cEnd; ++cIt)
              if ((*cIt)->traverseMode() & BaseNode::SecondPass)
                traverse_all(*cIt, _action);
        }

        // If the children had to be rendered first, we now render the node afterwards
        if (_node->traverseMode() & BaseNode::ChildrenFirst)
          _action(_node);

        // Call the leave function of the node.
        if_has_leave (_action, _node);
    }
}

//---------------------------------------------------------------------------------

template <class Action>
void
traverse_multipass ( BaseNode* _node, Action& _action, const unsigned int& _pass )
{

  // Process node if it exists
  if (_node) {
    BaseNode::StatusMode status(_node->status());


    // If the subtree is hidden, ignore this node and its children while rendering
    if (status != BaseNode::HideSubtree) {

      bool process_children(status != BaseNode::HideChildren);

      // Executes this nodes enter function (if available and active in multipass)
      if ( _node->multipassStatusActive(_pass) ) {
        if_has_enter(_action, _node);
      }

      // If the node itself is hidden, don't call the action on it.
      // Additionally check if rendering order is node first. otherwise, we will call it after the children.
      // And check if it should be called in this rendering pass.
      if ( (_node->status() != BaseNode::HideNode )  && ( _node->traverseMode() & BaseNode::NodeFirst ) && _node->multipassNodeActive(_pass))
        process_children &= _action(_node);

      if (process_children) {

        BaseNode::ChildIter cIt, cEnd(_node->childrenEnd());

        // Process all children
        for (cIt = _node->childrenBegin(); cIt != cEnd; ++cIt)
          if (~(*cIt)->traverseMode() & BaseNode::SecondPass)
            traverse_multipass(*cIt, _action, _pass);

        // Process all children which are second pass
        for (cIt = _node->childrenBegin(); cIt != cEnd; ++cIt)
          if ((*cIt)->traverseMode() & BaseNode::SecondPass)
            traverse_multipass(*cIt, _action, _pass);

      }


      // If we are in childrenfirst node, the children have been painted andwe now check, if we can draw this node.
      // If its hidden, ignore it.
      // If it should not be rendered in this pass, ignore it too.
      if ( (_node->traverseMode() & BaseNode::ChildrenFirst ) && (_node->status() != BaseNode::HideNode) && _node->multipassNodeActive(_pass) )
        _action(_node);

      // Call the leave function of the node (if available and active in multipass).
      if ( _node->multipassStatusActive(_pass) )
        if_has_leave(_action, _node);

    } // if (status != BaseNode::HideSubtree)
  } // if(node_)
}


//----------------------------------------------------------------------------

template <class Action>
void
traverse_multipass( BaseNode*           _node,
                    Action&             _action,
                    GLState&            _state,
                    DrawModes::DrawMode /*_drawmode*/=DrawModes::DEFAULT)
{
    // Reset render pass counter
    _state.reset_render_pass();

    // Get max render passes
    unsigned int max_passes = _state.max_render_passes();

    // Render all passes
    for(unsigned int pass = BaseNode::PASS_1; pass <= (BaseNode::PASS_1 + max_passes); ++pass) {

        // Traverse scenegraph
        traverse_multipass (_node, _action, pass);
        // Increment render pass counter by 1
        _state.next_render_pass();
    }

    // Reset render pass counter
    _state.reset_render_pass();
}

//--------------------------------------------------------------------------------

class BoundingBoxAction
{
public:

  BoundingBoxAction() :
    bbMin_( FLT_MAX,  FLT_MAX,  FLT_MAX),
    bbMax_(-FLT_MAX, -FLT_MAX, -FLT_MAX),
    state_(false)
  { }

  bool operator()(BaseNode* _node)
  {
    Vec3d bbMin( FLT_MAX,  FLT_MAX,  FLT_MAX);
    Vec3d bbMax(-FLT_MAX, -FLT_MAX, -FLT_MAX);
    _node->boundingBox(bbMin, bbMax);

    if ((bbMin[0] > bbMax[0]) ||
        (bbMin[1] > bbMax[1]) ||
        (bbMin[2] > bbMax[2]))
      return true;

    bbMin_.minimize(state_.modelview().transform_point (bbMin));
    bbMin_.minimize(state_.modelview().transform_point (bbMax));
    bbMax_.maximize(state_.modelview().transform_point (bbMin));
    bbMax_.maximize(state_.modelview().transform_point (bbMax));
    return true;
  }

  void enter (BaseNode *_node)
  {
    _node->enter(state_, DrawModes::DEFAULT);
  }

  void leave (BaseNode *_node)
  {
    _node->leave(state_, DrawModes::DEFAULT);
  }

  const Vec3d& bbMin() const { return bbMin_; }
  const Vec3d& bbMax() const { return bbMax_; }

private:

  Vec3d        bbMin_, bbMax_;
  GLState      state_;
};


//-----------------------------------------------------------------------------


class MultiPassInfoAction
{
public:

  MultiPassInfoAction() :
    statusPasses_(BaseNode::ALLPASSES),
    nodePasses_(BaseNode::ALLPASSES)
  {}

  bool operator()(BaseNode* _node) {

      // Get status pass 
      BaseNode::MultipassBitMask statusPass = _node->multipassStatus();

      // Ignore if set to ALLPASSES as we want to get the real maximum pass number
      if ( statusPass != BaseNode::ALLPASSES) {
        // Convert render pass bit mask to
        // decimal value (0x001011 -> 4)
        // Note: Same as (int)log2(bitmask)
        unsigned int c = 0;
        
        // Skip the first one as this is the ALLPASSES flag
        statusPass = statusPass >> 1;
        
        while( statusPass != 0u ) {
          statusPass = statusPass >> 1;
          ++c;
        }
        statusPasses_ = c > statusPasses_ ? c : statusPasses_;
      }
      
      
      // Get Node pass 
      BaseNode::MultipassBitMask nodePass = _node->multipassNode();
      
      // Ignore if set to ALLPASSES as we want to get the real maximum pass number
      if ( nodePass != BaseNode::ALLPASSES) {
        // Convert render pass bit mask to
        // decimal value (0x001011 -> 4)
        // Note: Same as (int)log2(bitmask)
        unsigned int c = 0;
        
        // Skip the first one as this is the ALLPASSES flag
        nodePass = nodePass >> 1;
        
        while(nodePass != 0u) {
          nodePass = nodePass >> 1;
          ++c;
        }
        nodePasses_ = c > nodePasses_ ? c : nodePasses_;
      }

      return true;
  }

  unsigned int getMaxPasses() const { 
    unsigned int maxpasses = std::max(statusPasses_,nodePasses_);
    
    // if maxpasses is 0 we have all nodes in ALLPASSES mode so we render only once
    return maxpasses == 0 ? 1 : maxpasses; 
  }

  unsigned int getStatusPasses() { return statusPasses_ == 0 ? 1 : statusPasses_; };
  
  unsigned int getNodePasses() { return nodePasses_ == 0 ? 1 : nodePasses_; };

private:

  unsigned int statusPasses_;
  unsigned int nodePasses_;
  
};


//----------------------------------------------------------------------------


class FindNodeAction
{
public:

  FindNodeAction(unsigned int _node_id) :
    node_id_(_node_id), node_ptr_(0)  {}

  bool operator()(BaseNode* _node)
  {
    if (_node->id() == node_id_)
    {
      node_ptr_ = _node;
      return false;
    }
    return true;
  }

  BaseNode*  node_ptr() { return node_ptr_; }

private:

  unsigned int  node_id_;
  BaseNode*     node_ptr_;
};


ACGDLLEXPORT
BaseNode* find_node( BaseNode* _root, unsigned int _node_idx );

ACGDLLEXPORT
BaseNode* find_hidden_node( BaseNode* _root, unsigned int _node_idx );


//----------------------------------------------------------------------------


class CollectDrawModesAction
{
public:

  CollectDrawModesAction() : drawModes_(DrawModes::NONE) {}

  bool operator()(BaseNode* _node)
  {
    drawModes_ |= _node->availableDrawModes();
    return true;
  }

  DrawModes::DrawMode drawModes() const { return drawModes_; }

private:

  DrawModes::DrawMode drawModes_;
};

//----------------------------------------------------------------------------


class CollectActiveDrawModesAction
{
public:

  CollectActiveDrawModesAction() : drawMode_(DrawModes::NONE) {}

  bool operator()(BaseNode* _node)
  {
    drawMode_ |= _node->drawMode();
    return true;
  }

  DrawModes::DrawMode drawMode() const { return drawMode_; }

private:

  DrawModes::DrawMode drawMode_;
};

//----------------------------------------------------------------------------


class SetDrawModesAction
{
public:

  SetDrawModesAction(DrawModes::DrawMode _mode, bool _force = false ) : newModes_(_mode),force_(_force) {}

  bool operator()(BaseNode* _node)
  {
    if ( newModes_ == DrawModes::DEFAULT )
      _node->drawMode( DrawModes::DEFAULT );

    DrawModes::DrawMode availableModes = _node->availableDrawModes();

    if ( force_ ) {
      // if force, we ignore if the mode is supported by the node and set it
      _node->drawMode( newModes_ );
    } else if ( availableModes & newModes_ ) {
      // If its supported, we set it
      _node->drawMode( availableModes & newModes_ );
    } else {
      // otherwise we switch the node to default draw mode (which will use the global mode)
      _node->drawMode( DrawModes::DEFAULT );
    }
    
    
    return true;
  }

private:
  DrawModes::DrawMode newModes_;
  bool                force_; 
  
};


//----------------------------------------------------------------------------


class DrawAction
{
public:

  DrawAction(DrawModes::DrawMode _drawMode, GLState& _state, bool _blending) : 
     state_(_state),
     drawMode_(_drawMode), 
     blending_(_blending) {}

  bool operator()( BaseNode* _node )
  {
    // draw only if Material status == DrawAction status
    if(state_.blending() == blending_)
    {
      _node->setDirty (false);
      if (_node->drawMode() == DrawModes::DEFAULT)
        _node->draw(state_, drawMode_);
      else
        _node->draw(state_, _node->drawMode());
    }
    return true;
  }
  
  void enter(BaseNode* _node)
  {
    if (_node->drawMode() == DrawModes::DEFAULT)
      _node->enter(state_, drawMode_);
    else
      _node->enter(state_, _node->drawMode());
  }
  
  void leave(BaseNode* _node)
  {
    if (_node->drawMode() == DrawModes::DEFAULT)
      _node->leave(state_, drawMode_);
    else
      _node->leave(state_, _node->drawMode());
  }

private:

  GLState&            state_;
  DrawModes::DrawMode drawMode_;
  bool                blending_;
};


//----------------------------------------------------------------------------


class ACGDLLEXPORT PickAction
{
public:

  PickAction(GLState &_state, PickTarget _target, DrawModes::DrawMode _drawmode) :
    state_(_state),
    pickTarget_(_target),
    drawmode_(_drawmode) {}

  bool operator()(BaseNode* _node);
  
  bool operator()(BaseNode* _node, GLState& _state);

  void enter(BaseNode* _node)
  {
    if (_node->drawMode() == DrawModes::DEFAULT)
        _node->enterPick(state_, pickTarget_, drawmode_);
      else
        _node->enterPick(state_, pickTarget_, _node->drawMode());
  }

  void leave(BaseNode* _node)
  {
    if (_node->drawMode() == DrawModes::DEFAULT)
        _node->leavePick(state_, pickTarget_, drawmode_);
      else
        _node->leavePick(state_, pickTarget_, _node->drawMode());
  }

private:

  GLState             &state_;
  PickTarget          pickTarget_;
  DrawModes::DrawMode drawmode_;
};


//----------------------------------------------------------------------------


class MouseEventAction
{
public:


  MouseEventAction(QMouseEvent* _event, GLState& _state) : 
    state_(_state),
    event_(_event) {}

  bool operator()(BaseNode* _node )
  {
    _node->mouseEvent(state_, event_);
    return true;
  }

private:
  GLState&     state_;
  QMouseEvent* event_;
};

//----------------------------------------------------------------------------


class CheckDirtyAction
{
public:


  CheckDirtyAction() : dirty_(false) {}

  bool operator()(BaseNode* _node)
  {
    dirty_ |= _node->isDirty();
    // don't traverse children if current node is _dirty
    return !dirty_;
  }

  bool isDirty() const { return dirty_; };

private:

  bool dirty_;
};


//=============================================================================
} // namespace SceneGraph
} // namespace ACG
//=============================================================================
#endif // ACG_SCENEGRAPH_HH defined
//=============================================================================